Projectile containment system

ABSTRACT

Converging hardened steel plates are loosely mounted in a frame, with neoprene pads between them to better absorb the noise and impact from projectiles. The upstream end of the bullet trap is a target area, and a containment chamber communicates with the downstream ends of the plates defines a throat area. A transition area connects the chamber entry with the throat area. An impact plate between them has end portions fitted loosely in openings defined by the support frame. A plurality of vanes define the cylindrical chamber, and have loosely supported ends. These vanes have edges that abut and over-lap one another so movement of adjacent vanes will occur in response to one of these vanes being struck by a projectile. These vanes are normally restrained but can move radially outwardly when hit by a projectile. The number of vanes is less than 20 degrees in the chamber.

CROSS REFERENCE TO RELATED APPLICATIONS

This application incorporates by reference U.S. patent application Ser.No. 13/475,511 filed May 18, 2012 and claims priority thereto in so faras common subject matter/invention is included.

FIELD OF INVENTION

This invention relates to projectile containment systems such as mightbe required at firing ranges or the like, and deals more particularlywith a bullet trap of the type having an open front end in which atarget can be provided, and a steel structure for decelerating theseprojectiles and containing the projectiles fired at that target by ashooter located at a station some distance from the target. Such bullettraps are generally made from steel plates that are welded or boltedtogether in a structure that can include converging hardened steelplates defining a convergent passageway that directs the projectilesfrom the target area toward a projectiles containment chamber where theyare collected for disposal.

PRIOR ART

Bullet traps of such steel plate construction are available from MegittTraining Systems of Suwanee Ga., and from Action Target of Provo, Utah.These bullet traps typically have upper and lower converging steelplates that direct the projectiles into an impact area so arranged as toabruptly decelerate the projectiles and contain them in a chamber. Thischamber can be of generally semi-cylindrical shape, with a bottomopening and a tray for reclaiming the lead and other spent materials.U.S. Pat. No. 7,793,937 shows a trap of this variety, wherein asemi-cylindrical impact area of the chamber defined by replaceablehardened steel strips that are fixedly supported on flanges in the framestructure. One major disadvantage of this design is the very rigidity ofthe steel structure itself. Hardened steel, such as AR500 for example,tends to wear away, and become pitted, by the impact of the leadprojectiles, leading to the need for replacement of the hardened steelstrips. AR500 steel is not readily welded or machined by conventionalheat generating fabrication processes, and poses a definite disadvantageto building and maintaining these prior art designs.

Thus, there is a need for improving upon both the cost of building andmaintaining the hardened steel components of such traps, particularly inreducing the downtime and the expense required for removing andreplacing the hardened steel turning vanes or strips that form thearcuately shaped containment chamber.

The need for replacing the hardened steel components used in thesebullet traps has lead to excessive costs in both initial purchase ofsuch traps, and in the upkeep thereof. Hardened steel, such as AR500, isnot readily welded or machined, hence anything that can be done toreduce the fabrication costs will result in savings to both themanufacturer, and to the user in the form of reduced repair andmaintenance costs. Additionally, there is a need to reduce the footprintof the structure to render it useable in a confined environment such asin the basement of a private residence, or similar space. Finally, suchan environment also requires a substantial reduction in the noisegenerated in a steel bullet trap. This goal is facilitated in the trapof my invention.

SUMMARY OF THE INVENTION

The very rigidity of the steel frame, and of the hardened steelcomponents from which the trap components are made, particularly in theimpact area, in which one or more angled hardened steel plates areserially arranged to slow projectiles. These plates are, therefore,subject to wearing. There is a need to minimize this excessive wearingaway and pitting of the hardened steel that results from the projectilesrepeatedly striking the impact area of the trap.

The present invention provides a hardened steel containment chambercapable of absorbing the energy and momentum of high velocityprojectiles in an energy efficient way, and without the shock and noisecharacteristic of prior art bullet traps. An impact plate of hardenedsteel deflects the projectiles into a containment chamber defined byelongated projectile turning vanes, or strips, that are so mounted as toabsorb the inertial impact of a projectile. These vanes have overlappingedges that interact with one another in a unique way. The vanes are notfixed in the static frame, but are instead resiliently mounted so as tomore efficiently absorb projectile impact. Each hardened steel strip, orvane, is mounted in an oversize opening of the steel frame supportstructure. More particularly, projecting end portions of these vanes arereceived in openings of slightly greater depth than the thickness of thevane end portions. The vanes are mounted in overlapping relationship,such that their adjacent edges overlap, causing each vane to effect anadjacent vane when struck by a projectile. As a result, at least twovanes will move slightly in reaction to one vane being impacted. Theimpact of the projectiles on these vanes is thereby absorbed moreefficiently. A resilient elastomeric blanket is provided around theoutside of the containment chamber defining vanes, and the blanket isbiased radially inwardly, holding the vanes against the inside edges oftheir respective openings. The vane edges are thus held in engagementwith one another, at least in their rest or ready positions, and will bedisplaced slightly in their respective openings in reacting to theimpact and momentum of the projectiles, efficiently absorbing the energythereof. The vanes are also biased inwardly by tensionable strapssurrounding the elastomeric blanket. Allowing the vanes to move uponimpact also reduces damage to these hardened steel vanes. The biasingforce is achieved by wrapping at least one tensionable band or strap atleast around the impact area of the containment chamber.

Another advantage to this unique yieldable vane mounting design is thereduction in the ambient noise level. Reducing the impact forces,between the hardened steel vanes and the lead projectiles, leads to avery significant reduction in the ambient noise level. This is a veryimportant result, where the noise can create severe environmentalconcerns, such as in any confined area.

In accordance with the preferred embodiment of the invention, atransition passageway is provided between the downstream end of theconvergent projectile passageway described previously and thecontainment chamber. This transition passageway includes a firstsegment, that forms a continuation of the throat area defined at thedownstream ends of the converging plates, plus a second segment in whicha single angled impact plate deflects projectiles slightly for directingthem into an inlet opening of the containment chamber. The containmentchamber is preferably cylindrical in shape, and the axis is verticallyoriented, rather than horizontal as in my prior filed application. Thisgeometry minimizes the footprint of the bullet trap itself, and thespent projectiles are collected at the bottom end of the verticallyoriented chamber for funneling the bullets and bullet fragmentsdownwardly into a 5 gallon bucket or similar container. The noxiousgasses generated in the chamber are vented to a filter through anopening in the top of the vertically oriented cylinder.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of a bullet trap constructed in accordancewith the present invention, with the upper top plate removed to bettershow the interior thereof.

FIG. 2 is a horizontal sectional view showing the transition passagewayand containment chamber in greater detail.

FIG. 3 is a side elevational view showing the angled top and bottomplates supported on legs and defining the fixed frame of the apparatus.

FIG. 4 shows the portion of the top plate defining the vane openings forthe vanes which define the containment chamber, and showing additionalopenings for receiving plates defining the transition passageway,including the parallel plates plus the impact plate.

FIG. 5 is shows the funnel at the lower open end of the containmentchamber.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

In it's presently preferred form the bullet trap shown in the drawingswill accommodate a single shooter located some distance upstream of thebullet trap. This distance will be dictated mostly by safetyconsiderations, but will also be dictated by the type of firearm used,and by the immediate environment for the shooter's location relative tothe bullet trap. The design is intended to minimize the foot printrequired, and the open/upstream end A, in which the target is mounted,is intended to be 25 feet from the shooter's station.

The bullet trap of FIG. 1 has an open front end A, or target area ofrectangular shape, into which the projectiles are fired by the shooter.As shown in FIGS. 1 and 3 the rectangularly shaped target opening A ofthe bullet trap has it's longer axis oriented vertically (FIG. 3) andthe shorter axis oriented horizontally (FIG. 1). The top and bottomplates 10,10, converge slightly (FIG. 3) and have angle iron supportswelded to or bolted to these fixed support plates. These support platesdefine over sized slots 10 a, 10 a for receiving projecting tabsintegrally formed at spaced locations on the edges of the more steeplyinclined hardened steel converging plates 16 and 18. See FIG. 2 of myco-pending application for details on this mounting arrangement, whereinan elastomeric strip 22 is provided between each angle iron flange andthese hardened steel plate tabs. This arrangement serves a twofoldpurpose; one to more efficiently absorb the impact of projectilesstriking the hardened steel plates 16 and 18, and secondly to reducesignificantly the noise created by such projectile/plate impact. Thesetop and bottom plates 10,10 are angled toward one another atapproximately 15 degrees with reference to the downstream direction soas to accommodate the projectiles fired into the bullet trap targetopening from the shooter's station, which is located upstream somedistance from the bullet trap. Preferably, and as shown in FIG. 3 thisangle is no more than about 15.5 degrees relative to the downstreamdirection. This allows non-hardened steel to be used for the framedefining steel support plates of the bullet trap.

The edges of the support plates 10,10 defining the target area A arepreferably beveled inwardly to avoid deterioration due to bulletsstriking them, and holes 15,15 in provided in these support plates 10,10are provided for receiving bungee cords, preferably of poly-urethane, tomount the paper target in the area A, Non-metallic “clothespins” may beused to clip the target to these cords.

The lateral sides of the rectangular target opening A are defined byforwardly facing vertical edges of the converging hardened steel plates,16 and 18. These plates are preferably made from AR 500 steel, and maybe oriented at more than the 15 degrees, an empirically determined limitreferred to previously with reference to the non-hardened steel supportplates 10,10.

In the detailed plan view of FIG. 2, the transition passageway D and thecontainment chamber C of FIG. 1, can be seen to include slots forreceiving parallel plates and an angled impact plate arranged oppositeto the vertically oriented containment chamber inlet. These parallelplates plus the impact plate define the transition zone D. Thecontainment chamber C being defined by the generally cylindrical shapeshown for the oversize vane openings that receive individual bulletturning vanes arranged at angles that gradually increase, hencegradually change the direction and speed of the bullets as they aredecelerated inside this chamber C. Note that inside the containmentchamber these vane angles vary slightly around the arcuate interior, buteach vane is generally oriented at an angle in the range of 15-20degrees relative to an adjacent vane. Thus, the projectile containmentchamber C is similar to that described in my co-pending application, buthas its axis oriented vertically rather than horizontally as in theprior version of my invention.

The containment chamber C is provided downstream of a throat area Bdefined at the downstream edges of the convergent hardened steel plates16 and 18 and a transition passageway D provided between the throat areaB and the containment chamber C. Whereas the horizontally arrangedcontainment chamber of my earlier application required access to theinterior by a side opening, the vertically oriented chamber of thepresent invention is simply fitted with a bottom opening having a funnelF for guiding the spent bullet fragments to drop into a waste bucket Wbelow the funnel F. This chamber C has a top opening, see FIG. 4, fittedwith a hose H for sucking out the lead laden air, and delivering thistoxic air to an air filtration system 28 located on or adjacent thebullet trap frame.

The containment chamber vanes have end portions fitted in oversize vaneopenings as in the prior application, and have overlapping longitudinaledges that create complementary vane movement. Not only is the vanestruck moved slightly due to the greater vane opening width, than vanethickness, but, the overlapping vanes cause complementary movement of atleast one adjacent vane. Thus limited vane movement is provided for, butis restricted both by the vane opening size and shape and by theoverlapping vane edges. A third factor effecting vane movement isachieved in this improvement as in the prior application, by wrapping acompressible elastomeric blanket 40 around the outside of the vanes, andby applying radially inwardly compressive forces on this blanket bytensioning straps around the elastomeric blanket.

The adjacent vanes are thus held in edge to edge contact with oneanother and biased inwardly of their respective slots as suggested inFIG. 4 of the prior filed co-pending application (top balloon view).When a vane is struck by a projectile, it twists slightly (as suggestedin the FIG. 4 sequence of the prior application). Each projectile isdecelerated both by impacting successive vanes, and by theaforementioned vane edge interaction. The above sequential views showthe vane downstream of that vane actually struck, moving even withoutitself being struck by the projectile, and in an opposite angulardirection.

In summary, adjacent turning vanes 30,30 have interacting trailing andleading edges, such that the trailing edge of an upstream vane liesinside the leading edge of a downstream vane. Thus, the vanes arenormally biased inwardly, but adjacent vanes will be angularly displaced(oppositely) upon impact by a projectile at even slight angles of attackwith the upstream vane. Stated somewhat differently, the vane leadingedges define an arc of larger radius than the arc defined by thetrailing edges, at least when the vanes are in their normal positions,as dictated by the restraining blanket and strap(s).

In the preferred embodiment shown, only one impact plate is providedopposite the entry opening of the containment chamber C, and is orientedat an angle in the range of 10-15 degrees, preferably 17 degreesrelative the downstream direction (as indicated by the parallel plateslots X and Y in FIG. 2. Furthermore, in the transition zone, betweenthe throat area B and the chamber opening, these parallel plates X and Yform a continuation of and bound the same area as that of the throat B

What is claimed is:
 1. Projectile containment system for trapping bullets therein, and comprising: A) at least two opposing generally flat hardened steel plates defining a convergent passageway for directing the bullets downstream into a throat area defined by the downstream ends of said two opposing plates, B) a containment chamber, defined by a plurality of hardened steel vanes arranged in side by side overlapping relationship to form a generally cylindrically shaped chamber having an inlet opening oriented at a substantial angle to the plane defined by said downstream ends of said hardened steel plates, C) a support frame having side/support plates defining vane openings for loosely receiving end portions of said turning vanes, and vane biasing means acting on said turning vanes to urge at least the majority of said vanes radially inwardly of said containment chamber to impede and turn the bullets entering said chamber inlet opening, D) a transition passageway between said throat area and said containment chamber inlet opening, said transition passageway defined by opposing transition inlet plates forming an extension of said throat area, and at least one impact plate/vane provided downstream of one of said opposing inlet plates and oriented at an angle of less than 15 degrees relative one of said opposing transition inlet plates, said impact plate/vane having a downstream edge provided adjacent to a first turning vane defining a downstream edge of said chamber inlet opening, said first turning vane oriented at an angle of approximately 20 degrees relative to said impact plate/vane.
 2. The containment system of claim 1 wherein said vane biasing means comprises at least one tensioned band wrapped around at least a portion of said impact boundary of said containment chamber, and a compressible elastomeric blanket provided between said vanes and said tensioned band to urge said vanes inwardly.
 3. The containment system of claim 2 wherein said overlapping adjacent vane edges are so arranged that the leading edges define an arc of larger radius than the arc defined by said trailing edges when said vanes are in said normal positions.
 4. The containment system of claim 1 further characterized by a transition passageway between said throat area and said containment chamber inlet opening, said transition passageway having boundaries defined by projectile guiding generally parallel plates forming a continuation of said throat area, and said single impact plate oriented opposite the inlet opening of said containment chamber.
 5. The containment chamber of claim 1 wherein said generally cylindrical containment chamber has a central axis oriented generally vertically, and said cylindrical chamber having a bottom opening through which spent projectile fragments fall downwardly out of said chamber.
 6. The containment chamber of claim 5 wherein said cylindrical chamber has a top opening, and suctioning means coupled to said containment chamber top opening for withdrawing air and air entrained particles from said chamber.
 7. The containment system of claim 1 further characterized by said transition passageway between said throat area and said containment chamber inlet opening more particularly defined by opposing projectile guiding generally parallel plates that together form a continuation of said throat area, and a single impact plate opposite the entry opening into said containment chamber.
 8. The containment system of claim 16 wherein each vane has marginal edges overlapping a marginal edge of at least one adjacent vane, whereby tilting movement of one vane causes tilting movement of that adjacent vane
 9. The containment system of claim 1 further characterized by said opposing hardened steel plates defining said convergent passageway loosely mounted in openings defined by frame support plates, and elastomeric pads provided adjacent to projecting tabs defined by side edges of said opposing hardened steel plates, said frame support plate openings fitted with flanges abutting said elastomeric pads.
 10. The containment system of claim 9 wherein said frame support plates fitted with said flanges comprise non hardened steel and define opposing sides of said convergent passageway, and said support plates also being inclined inwardly to form a rectangular shape for said throat area, the longer sides of which rectangular throat area defined by said hardened steel plates, the shorter sides being defined by said non hardened steel support plates. 